Volkswagen ID.3: Air conditioner. Locating leaks

• General notes on locating leaks in refrigerant circuit
• Locating leaks with pressure test using nitrogen
• Locating leaks using forming gas
• Locating leaks using electronic leak detector
• Locating leaks using UV leak detection system

General notes on locating leaks in refrigerant circuit

General notes on locating leaks in refrigerant circuit

This Workshop Manual includes descriptions of all procedures for locating leaks that have been approved for this refrigerant by the manufacturer.

♦ Refrigerant circuits with leaks must not be charged with refrigerant.

♦ The methods for locating leaks must be selected on a case by case basis. Different methods are required depending on the size of the leak.

♦ For example, the following methods can be used to locate minor leaks → Rep. gr.87; Locating leaks using electronic leak detector, → Rep. gr.87; Locating leaks using UV leak detection system or → Rep. gr.87; Locating leaks using forming gas.

♦ Minor leaks in the refrigerant circuit cannot generally be located using the vacuum test or pressure test. The quantity of air entering or the quantity of test gas escaping is not sufficient to produce any noise which would help to identify the location of the leak.

♦ Major leaks in the refrigerant circuit can be detected with the vacuum test or pressure test, e.g. on the basis of noises occurring at the locations of the leaks during these tests → Rep. gr.87; Locating leaks using vacuum test or → Rep. gr.87; Locating leaks with pressure test using nitrogen.

♦ Leaks in the refrigerant circuit with a refrigerant loss of more than 100 g of refrigerant per year cannot always be detected with the vacuum test or pressure test, depending on the ambient conditions (ambient noises, location of leaks, etc.). The quantity of air entering or the quantity of nitrogen escaping may not be sufficient to produce any noise which would make it possible to identify the location of the leak → Rep. gr.87; Locating leaks using forming gas.

Locating leaks with pressure test using nitrogen

Locating leaks with pressure test using nitrogen

Special tools and workshop equipment required

♦ Nitrogen cylinder

♦ pressure gauge set with nitrogen pressure reducer

♦ service coupling

Preparing tools

– Connect pressure gauge set with nitrogen pressure reducer (maximum reducing pressure: 13.5 bar) -1- to compressed-nitrogen cylinder -3- and filler hose -2- (e.g. with M12 x 1.5 -6G thread according to SAE J639).

– Connect service coupling to filler hose -2-.

Procedure

Important

● Refrigerant circuit assembled

● Refrigerant circuit discharged

– If possible, evacuate refrigerant circuit → Rep. gr.87; Evacuating refrigerant circuit.

Vehicles with electrical air conditioner compressor:

DANGER

High voltage can cause fatal injury.

Danger of severe or fatal injuries from electric shock or electric arcs.

– Have a high-voltage technician (HVT) or a high-voltage expert (HVE) de-energise the high-voltage system.

– → Motor; Rep. gr.93; De-energising high-voltage system.

All vehicles (continued)

Vehicles with mechanical air conditioner compressor:

NOTICE

Risk of insufficient lubrication if a refrigerant circuit is filled with test gas.

Risk of damage to air conditioner compressor

– Do not start vehicle.

– Mark vehicle accordingly.

– Ensure that vehicle is not started while refrigerant circuit is charged with nitrogen.

All vehicles (continued)

– Close pressure reducer → operating instructions.

– Increase pressure in refrigerant circuit slowly in stages (to maximum of 13.5 bar).

– Identify location of leak on basis of noises.

– Release nitrogen via pressure reducer → operating instructions.

– Repair leak.

– After using nitrogen, evacuate refrigerant circuit for at least 30 min.

Locating leaks using forming gas

Locating leaks using forming gas

Special tools and workshop equipment required

♦ 95/5 forming gas cylinder that meets DIN EN ISO 14175 standard (commercially available)

♦ gas leak detector -VAS 523 003-

♦ pressure reducer -VAS 584 007-

Procedure

Important

● Refrigerant circuit assembled

● Refrigerant circuit discharged

– If possible, evacuate refrigerant circuit → Rep. gr.87; Evacuating refrigerant circuit.

Vehicles with electrical air conditioner compressor:

DANGER

High voltage can cause fatal injury.

Danger of severe or fatal injuries from electric shock or electric arcs.

– Have a high-voltage technician (HVT) or a high-voltage expert (HVE) de-energise the high-voltage system.

– → Motor; Rep. gr.93; De-energising high-voltage system.

All vehicles (continued)

Vehicles with mechanical air conditioner compressor:

NOTICE

Risk of insufficient lubrication if a refrigerant circuit is filled with test gas.

Risk of damage to air conditioner compressor

– Do not start vehicle.

– Mark vehicle accordingly.

– Ensure that air conditioner compressor is not started while refrigerant circuit is charged with forming gas.

All vehicles (continued)

– Charge refrigerant circuit with forming gas slowly in stages via pressure reducer -VAS 584 007- (to maximum pressure of 13.5 bar) → operating instructions.

– Examine refrigerant circuit with gas leak detector -VAS 523 003-.

♦ Examine connections and coupling points from all sides.

♦ When performing examination, move gas leak detector -VAS 523 003- along refrigerant lines slowly (1 cm per sec.).

♦ The evaporator can be examined via the vents, e.g. the defroster vent. To improve detection, the vent opening can be reduced in size with adhesive tape.

– Release forming gas via pressure reducer -VAS 584 007- → operating instructions.

– Repair leak.

– After using forming gas, evacuate refrigerant circuit for at least 30 min.

Locating leaks using electronic leak detector

Locating leaks using electronic leak detector

Special tools and workshop equipment required

♦ leak detector -VAS 584 001-

This procedure can only be used if the refrigerant circuit is fully or partially charged. If the refrigerant circuit is fully discharged as a result of the leak, it must not be charged. Use a different method in this case → Rep. gr.87; Locating leaks

Procedure

Vehicles with high-voltage system:

– Deactivate auxiliary air conditioner function → Owner's Manual.

– Switch off ignition.

All vehicles (continued)

– Start up leak detector -VAS 584 001- → operating instructions.

– Check potential locations of leak from all sides using leak detector -VAS 584 001-.

Important

● An increase in the number of clicking noises or a wailing noise (depending on the design of the leak detector) indicates that the leak has been found → operating instructions.

● Refrigerant dissipates quickly due to air currents. Draughts must be avoided during leak detection.

Locating leaks using UV leak detection system

Locating leaks using UV leak detection system

Special tools and workshop equipment required

♦ Leak detection additive

♦ air conditioner service station

♦ cleaning solution -VAS 6201/3-

♦ leak detection additive

♦ leak detection system -VAS 6201-

♦ sticker -VAS 6201/7-

♦ Refrigerant circuit leaks often result in a loss of refrigerant oil together with the refrigerant. A leak detection additive must be added to the refrigerant circuit to make this oil visible under UV light.

♦ Leaks that only occur when the air conditioner compressor is operating can be located with the UV leak detection system.

♦ Operate the air conditioner for at least 60 min. to allow the leak detection additive to distribute through the refrigerant circuit fully.

♦ Leak detection additive can be added to the open refrigerant circuit directly or after it has been discharged with the air conditioner service station → operating instructions.

Adding leak detection additive to the refrigerant circuit via the air conditioner service station

Important

● Vacuum test performed successfully → Rep. gr.87; Evacuating refrigerant circuit

– Charge refrigerant circuit with leak detection additive and refrigerant according to specifications → Rep. gr.87; Charging refrigerant circuit, → Heating, air conditioning; Rep. gr.00; Technical data; Refrigerant oil capacities and → Electronic parts catalogue.

Amount of leak detection additive:

♦ The amount of leak detection additive that must be used depends on the specified amount of refrigerant oil → Heating, air conditioning; Rep. gr.00; Technical data; Refrigerant oil capacities.

♦ Refrigerant circuits where specified amount of refrigerant oil is < 150 ml: 3.0 ±0.5 ml

♦ Refrigerant circuits where specified amount of refrigerant oil is larger (e.g. 250 ml): 5.0 ±0.5 ml

♦ Observe the following if leak detection additive has already been added to the refrigerant circuit in the course of previous repair work: Only add new leak detection additive if refrigerant oil has been renewed. If only some of the refrigerant oil has been renewed, just add the corresponding quantity of leak detection additive. For example, if 50 ml of refrigerant oil was renewed in a vehicle with a total of 150 ml, only add 1.0 ml of leak detection additive.

– After adding leak detection additive, mark refrigerant circuit with sticker -VAS 6201/7-.

– Clean residue of leak detection additive off service connections and surrounding area. Use absorbent paper and cleaning solution -VAS 6201/3- to do so.

Locating leaks with UV lamp from leak detection system -VAS 6201-

Important

● The air conditioner must have been operated for at least 60 min. to distribute the leak detection additive through the entire refrigerant circuit (the air conditioner compressor must be running).

– Position vehicle in a slightly darker area of workshop (the effect of the UV light is reduced in daylight or in strong lighting).

CAUTION

Risk of eye injuries from UV light.

– Wear UV safety goggles.

– Never look into the UV lamp.

– Never direct the UV lamp at other persons.

– Shine UV lamp on components of refrigerant circuit. Locations at which a leak has caused leak detection additive to emerge are lit up under UV light (fluorescent).

♦ Depending on the size and location of the leak, it may take several days for sufficient refrigerant oil with leak detection additive to emerge to enable the location of the leak to be identified clearly.

♦ Certain materials and their compounds (e.g. oxidation products on aluminium components, anti-corrosion waxes) also light up under UV light.

♦ In the event of leaks in the evaporator, the leak detection additive may be washed out with the condensation and emerge via the condensation drain. As considerable work is required on most vehicles to gain access to the evaporator, a check at the condensation drain (for example) can provide an indication of a leak in the evaporator. However, this requires the leak detection additive to have been in the refrigerant circuit for a lengthy period (several days).

♦ During air conditioner operation, only a small quantity of refrigerant oil reaches certain points of the refrigerant circuit (e.g. a cap on top of a receiver mounted on the condenser). In the event of leaks at such locations, it may take longer for a sufficient amount of refrigerant with refrigerant oil and leak detection additive to emerge. At such locations, it makes sense to use an electronic leak detector to locate a leak → Rep. gr.87; Locating leaks using electronic leak detector.

Air conditioner. Renewing componentsAir conditioner. Working with air conditioner service station